Ovicula biradiata, a new genus of Compositae from Big Bend National Park in Trans-Pecos Texas

$¢PhytoKeys

PhytoKeys 252: 141-162 (2025)
DOI: 10.3897/phytokeys.252.137624

Research Article

Ovicula biradiata, a new genus of Compositae from Big Bend
National Park in Trans-Pecos Texas

Debra L. Manley’™®, Isaac H. Lichter Marck®, Keily Peralta?, Arturo Castro Castro?®, Kelsey A. Wogan’,
Carolyn V. Whiting'’®, A. Michael Powell*

1 Science and Resource Management, Big Bend National Park, PO Box 129, Big Bend National Park, TX 79834-0129, USA
2 Department of Botany, Institute for Biodiversity Science and Sustainability, California Academy of Sciences, 55 Music Concourse Dr., San Francisco, CA

94118, USA

3 Centro Interdisciplinario de Investigacion para el Desarrollo Integral Regional, Sigma 119, Fracc. 20 de Noviembre II, Durango, Mexico
4 Department of Natural Sciences, Sul Ross State University, East Highway 90, Alpine, TX 79832, USA
Corresponding author: Isaac H. Lichter Marck (ilichtermarck@gmail.com)

OPEN Qaceess

Academic editor: Oscar Vargas
Received: 22 September 2024
Accepted: 20 December 2024
Published: 18 February 2025

Citation: Manley DL, Lichter Marck IH,
Peralta K, Castro Castro A, Wogan KA,
Whiting CV, Powell AM (2025) Ovicula
biradiata, a new genus of Compositae
from Big Bend National Park in
Trans-Pecos Texas. PhytoKeys 252:
141-162. https://doi.org/10.3897/
phytokeys.252.137624

Copyright: This is an open access article
distributed under the terms of the CCO Public
Domain Dedication.

Abstract

Here, we describe and illustrate a new monospecific genus of Compositae, Ovicula
biradiata gen. et sp. nov., from the Chihuahuan Desert in Big Bend National Park, Texas.
Ovicula biradiata is a very locally abundant, yet range-limited, spring annual herb found in
coarse calcareous alluvium. Based on its pistillate ray florets, pappus of hyaline, aristate
scales, tomentose foliage and slightly saucer-shaped to flat, epaleate receptacle, we
determine that the new species has affinities with the Helenioid subtribe Tetraneurinae in
the Heliantheae alliance. Molecular phylogenetic analysis of nrDNA (ITS) sequence data
supports the phylogenetic position of Ovicula biradiata within the subtribe Tetraneurinae,
where itis resolved as the sister lineage to the genus Psilostrophe. We also present detailed
habitat information, high-resolution images captured using a dissecting microscope and
scanning electron micrographs of vegetative and reproductive characters of Ovicula
biradiata and related taxa, as well as provide an updated key to the genera of Tetraneurinae.
Finally, we discuss the significance of this remarkable discovery for community science,
biodiversity exploration and plant conservation in the Chihuahuan Desert.

Resumen

Se ilustra y describe un nuevo género monoespecifico de Compositae, Ovicula biradiata
gen. et sp. nov., del Desierto Chihuahuense en el Parque Nacional Big Bend, Texas. Ovicula
biradiata es una hierba annual muy localmente abundante, pero con un rango limitado, flo-
rece en la primavera y se encuentra en aluviones calcareos gruesos. Con base en sus flores
pistiladas con corola radiada, vilano de escamas aristadas y hialinas, follaje tomentoso y
receptaculo ligeramente en forma de platillo a plano y epaleado, determinamos que la nue-
va especie tiene afinidades con Helenieae subtribu Tetraneurinae, en la alianza Heliantheae.
Analisis cladisticos moleculares de secuencias del ADN ribosomal nuclear (ITS) apoyan
la posicion filogenética de O. biradiata dentro de la subtribu Tetraneurinae, donde resulta
el lineage hermano del género Psilostrophe. También presentamos informacion detallada
sobre el habitat, imagenes de alta resolucion usando un microscopio de diseccion y micro-
grafias electronicas de barrido de caracteres vegetativos y reproductivos de O. biradiata y
taxa relacionados, asi como una clave actualizada para los géneros de Tetraneurinae. Final-
mente, discutimos la significancia del descubrimiento en relacion a la ciencia ciudadana,
exploracion de biodiversidad, y la conservacion de plantas en el Desierto Chihuahuense.

141

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

Key words: Asteraceae, biodiversity, calciphile, Chihuahuan Desert, Helenieae, taxono-
my, Tetraneurinae

Palabras clave: Asteraceae, biodiversidad, calcifilo, Desierto Chihuahuense, Helenieae,
taxonomia, Tetraneurinae

Introduction

The Chihuahuan Desert is the largest and most biologically diverse warm des-
ert in North America (Bell et al. 2014). Big Bend National Park is in southern
Brewster County, Texas, bordered to the south by the Rio Grande. Its 801,165
acres (324,220 hectares) include some of the best representation of Chihua-
huan Desert microhabitat diversity in the United States, including within the
Chisos Mountain range (highest elevation ca. 7825 ft. (2385 m)) and numer-
ous smaller peaks separated by low desert bajadas. Eighty-nine plant species
of conservation concern are found in the park (Louie 1996; Poole et al. 2007,
Texas Parks and Wildlife Department 2024). Many of these species of concern
have limited distributions that extend into adjacent areas in Mexico or into Chi-
huahuan Desert habitats to the immediate north and east of the park boundary
(Powell and Worthington 2018).

Previous floristic and wildflower studies centred in and near Big Bend Na-
tional Park, include McDougall and Sperry (1951), Warnock (1970, 1974, 1977),
Fenstermacher et al. (2008), Morey (2008, 2024), Hardy (2009), Weckesser and
Terry (2014) and Powell and Worthington (2018). Wauer (1973, 1997) explored
many off-the-trail areas searching for plants and animals of natural history in-
terest. Potentially relevant floristic treatises of wider range include Correll and
Johnston (1970), Henrickson et al. (1997), Turner et al. (2003), Turner (2013),
Eason (2018) and Allred et al. (2020). Even though the park has been rather
thoroughly botanised in the vicinity of most accessible areas, additional new
plant discoveries are possible because of its extensive habitat diversity in
stretches of remote terrain.

On 2 March 2024, while traversing cross country in search of rare plant popula-
tions, the first author photographed an anomalous composite and posted images
on iNaturalist. These diminutive plants, observed during the peak of their growing
season, were inconspicuous annuals, from less than one centimetre to 3-7 cen-
timetres across, prostrate and densely white-woolly, matching the whitish colour
of their calcareous gravel substrate (Figs 1-9). Following a review, Park author-
ities granted us permission to collect a few individuals for further study. From
the limited material on hand and the photos we had taken, we were able to dis-
cern characters suggestive of relationships to the tribe Helenieae Lindl. (sensu
Baldwin et al. (2002)), especially Tetraneuris Greene. These characters included
obconic fruits with five paleaceous, aristate scales and pistillate ray florets with
maroon linear markings (Bierner and Turner 2006; Funk et al. 2009; Spellenberg
and Zucker 2019). To test the hypothesised relationship to Helenieae, we carried
out a more detailed study of inflorescence and fruit characters using scanning
electron microscopy and sequenced nrDNA sequence data for one DNA gene
region, the Internal Transcribed Spacer (ITS). Here, we present morphological, mi-
cro-anatomical and molecular phylogenetic evidence that supports description
of this plant as a new genus and species of subtribe Tetraneurinae Rydb.

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624 142

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

Methods
Field and herbarium collections

After the National Park Service granted a research permit for this study (BIBE-
2024-SCI-0015), plants were collected from two field locations, briefly dried and
deposited in the A. Michael Powell (SRSC) and California Academy of Scienc-
es (CAS) Herbaria for mounting and further study. To our knowledge, besides
these collections, this previously unknown species has not been deposited in
herbaria before. Dried vegetative and reproductive material of putative close rel-
atives was obtained for detailed morphological study and DNA sequencing from
herbarium specimens at SRSU and CAS. Sampling included representatives of
genera in subtribe Tetraneurinae, i.e. Amblyolepis DC., Baileya Harv. & A. Gray ex
Torr., Hymenoxys Cass., Psilostrophe DC. and Tetraneuris Greene. A complete list
of specimens sampled and GenBank accession numbers is presented in Table 1.

Morphological study

We examined morphological characters from field collections of the new spe-
cies and exsiccate of putative close relatives using dissecting microscopy.
Images of microscopic features were captured using a Leica M60 stereomi-
croscope (Leica Camera, Wetztlar, Germany) outfitted with a digital camera.

Table 1. Specimen voucher data and GenBank accession numbers for herbarium material used in molecular phylogenet-
ic analyses and scanning electron microscopy.

Taxon

Psilostrophe bakeri Greene

Baileya pauciradiata Harv.
& A. Gray

Tetraneuris acaulis
(Greene) K.F. Parker var.
arizonica

Psilostrophe sparsiflora
(A.Gray) Nelson

Tetraneuris scaposa (DC.)
Greene

Baileya multiradiata harv. &
A. Gray

Amblyolepis setigera DC.

Psilostrophe villosa Rydb.
ex Britton

Hymenoxys cooperi
Cockerell var. cooperi

Psilostrophe mexicana
R.C. Br.

Psilostrophe gnaphalodes
DC.

Ovicula biradiata Manley

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624

: GenBank
Accession Collector :
Purpose Collector Date accession
number number
number

DNA/SEM CAS 818281 A. Cronsquist 11645 13 June 1980 PQ144335
SEM CAS 288097 H.S. Gentry 25 Feb 1933
SEM CAS 731062 J. Henrickson 10576 A June 1973

DNA CAS 5935742 M. Butterwick 7526 19 May 1981 PQ144336

DNA/SEM CAS 700109 B. Turner 15128 5 June 1983 PQ144339
SEM CAS 713832 P. Munz 13688 3 May 1935

SEM CAS 765096 B. Ertter 5598 13 March 1985

DNA CAS 507562 P. Raven 19297 7 June 1964 PQ144334
SEM CAS 1005608 J. Henrickson 10521 4 June 1973

DNA CAS 720959 J.L. Villasefior 1591 23 September 1982 PQ144337

DNA CAS 701425 S. Sunderberg 1214 15 August 1981 PQ144338

DNA/SEM | SRSC 00058752 D. Manley 2 17 April 2024 PQ144333

143

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

Table 2. Comparison of morphology amongst genera of subtribe Tetraneurinae.

Character/taxon

Life span

Stems

Leaves/blades

Heads/
peduncles

Involucres

Phyllaries

Ray florets

Disc florets

Cypselae

Pappus

Base
chromosome
number

Hymenoxys

Annual, biennial
or perennial

5-120+ long;
erect, often
branched;
glabrous or pilose

Basal and
cauline; simple
or 1—2-pinnately
lobed; glabrous or
pilose

Single or several;
peduncles 0.4-
20+ cm long

2.5-30 mm wide

2-3-seriate;
sparsely to
moderately pilose

(3-)8-13+;
corollas yellow to
orange, corollas
yellow to orange,
nerves colourless
or greenish; ray
floret corollas
0.7-12 mm wide

Usually 25-50+;
corollas yellow to
brownish-yellow,
1.5-7.4 mm
long; pubescent
distally, trichomes
to 0.2 mm long

Obconic or
obpyramidal,
1.4-4.7 mm long;
glabrous or pilose

None or of
ZT)
usually aristate,
obovate to
lanceolate,
scales, 0.8-
4.3 mm long

x=15

Tetraneuris

Annual or
perennial

5-50 cm long;
erect, or plants,
acaulescent;
sparsely to
densely pilose

Basal or basal
and cauline; linear
to lanceolate;
glabrous or pilose

Single or several;
peduncles 0.5-
40+ cm long

6-20 mm wide

3-seriate;
sparsely to
densely pilose

None or 7-27;
corollas yellow,
nerves colourless,
greenish,
sometimes
reddish-brown to
maroon; ray floret
corollas 2.5-6
mm wide

20-250+;
corollas yellow,
purplish distally,
1.6-3 mm long;
pubescent mainly
distally, trichomes
to 0.1-0.2 mm
long

Obconic or
obpyramidal,
1.5-4 mm long;
moderately
to densely
tomentose

Usually 4-8
aristate
lanceolate,
obovate, to
oblanceolate,
scales, 1-4.5 mm
long

x=15

Amblyolepis

Annual

Usually 12-
50 cm long; erect
to decumbent;
sparsely to
moderately pilose

Cauline; linear to
spatulate; pilose

Usually single;
peduncles to 20
cm long

12-20 mm wide

2-seriate;
sparsely to
moderately pilose

Usually 8-13;
corollas yellow,
nerves colourless
or greenish,
sometimes
darker than
background of
laminae; ray floret
corollas 4.5-10
mm wide

20--50; corollas
yellow, 5-7 mm
long; essentially
glabrous distally

Obconic, 3-4.5
mm long,
prominently
10-ribbed; ribs
densely tan-
tomentose

5-6 ovate scales
2-3.5 mm long

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624

Psilostrophe

Biennial,
perennial or
shrubby

8-50+ cm long;
spreading to
erect; often

densely woolly

Basal and
cauline; linear
to spatulate;

sparsely to

densely woolly

Single or
in clusters;
peduncles 0.5-
60+ cm long

2-7 mm wide

1-2-seriate;
densely woolly

1-8; corollas
yellow, nerves
greenish,
sometimes
darker than
background; ray
floret corollas
3-20 mm wide

5-25+; corollas

yellow to orange,
3.9-5.5.mmM

long; pubescent

distally, trichomes
0.1--0.2 mm long

Cylindrical
to clavate or
obpyramidal,
striate-ribbed,
2.5-4 mm long;
glabrous, gland-
dotted, or villous

4-8 oblong,
elliptic or
lanceolate,
scales, 1.5-3.2
mm long

Ovicula

Ephemeral annual

1-4 cm long;
prostrate; densely
woolly

Basal ovate,
involute to nearly
folded; densely
woolly

Single; sessile or
peduncles 1 mm
long

To 4-6 mm wide

3-seriate; densely
woolly

2 (-3); corollas
whitish, nerves
maroon; ray
floret corollas
0.6-1 mm wide

10-12; corollas

pale yellow, ca.

2--3 mm long;
tomentose

distally, trichomes

0.3-0.5 mm long

Obconic-
obpyramidal,
faintly ribbed,

1.5-2 mm
long; densely
tomentose

5 aristate, oval
scales, to 2 mm
long

Baileya

Annual,
biennial or
perennial

Usually 15-

75 cm long;

mostly erect;
woolly

Basal and
cauline; linear
to ovate, often

pinnately

lobed; often
densely woolly

Single or
several;
peduncles
2-12 cm long

5-25 mm wide

2-seriate;
moderately to
densely woolly

5=70r 20-55;
corollas
yellow, nerves
colourless to
greenish; ray
floret corollas
4-7 mm wide

10-20, or 40-
100+; corollas
yellow,
2.5-4mm
long; densely
pubescent
distally,
trichomes to
ca. 0.2 mm
long

Narrowly
obpyramidal,
3-4 mm long,
weakly ribbed

or striate;

glandular

Usually absent,
rarely scales

144

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

Morphology was compared with representatives of all recognised genera of
tribe Helenieae (Table 2). In addition, surface morphology of floral and vege-
tative structures was analysed and imaged using a Hitachi SU3500 Scanning
Electron Microscope (SEM; Hitachi, Tokyo, Japan) at the California Academy
of Sciences. Initially, inflorescence and fruit structures were disassembled un-
der a dissecting microscope and loaded on to an 18 mm pin-mounted SEM
stub using double sticky tape. To enhance the electron conductivity of sam-
ples, we then used a Cressington Sputter Coater 108 (Cressington, Watford,
UK) at a vacuum pressure of 0.8 Pa to apply a 5 nm layer of gold-palladium
to the sample for 50 seconds. We observed traits of potential phylogenetic
informativeness following Robinson (1981) and King and Robinson (1970) at
15 kV and a working distance of 7 mm, under automated controls for focus,
contrast and stigmation.

DNA extraction, amplification and sequencing

Following removal of the woolly indumentum under a dissecting microscope,
fresh, field-collected leaves were dried for one week using silica gel and
pulverised in a Qiagen tissue lyser (Qiagen, inc., Valencia, California) with
a mixture of zircon beads and autoclaved sand. Genomic DNA was extract-
ed using the DNEasy plant mini-kit (Qiagen, inc., Valencia, California) in the
Center for Comparative Genomics at the California Academy of Sciences.
We followed the provided protocol with a modified incubation in a cell-lysis
buffer extended to 16 hours. A Polymerase Chain Reaction (PCR) master mix
containing 9.1 ul H,0, 0.3 ul DnTPs, 0.15 ul Taq polymerase, 0.75 ul MgCl,
1.5 ul 10x PCR buffer and 0.6 ul Bovine serum Albumin (BVA) was com-
bined with two primers for amplifying the Internal Transcribed Spacer region
(ITS), ITS4 and LEU (White et al. 1990). Two ul of undiluted genomic DNA
was combined with the PCR master mix and transferred to a thermal cycler
programmed to the following conditions: 97 degrees for 1 min; 40 cycles of
97 degrees for 10 sec, 48 degrees for 30 sec, 72 degrees C for 20 seconds;
and 72 degrees C for 7 minutes. Post-PCR products were checked for suc-
cessful amplification using gel electrophoresis and unpurified PCR-product
was forward and reverse Sanger sequenced by Genewiz (Azenta US Inc.,
Burlington, MA).

Following an initial search of the NCBI BLAST database to confirm a close
match between our ITS sequence and putative closely-related taxa, we visually
aligned the ITS sequence for the new species with the Baldwin et al. (2002)
published data matrix for epaleate tribes of the Heliantheae alliance. Once
we recovered strong evidence for the sister relationship of the new species
with Psilostrophe in tribe Helenieae, we generated additional sequence data
for all recognised minimum-rank taxa of Psilostrophe and Tetraneuris scaposa
(DC.) Greene using leaf tissues sampled from herbarium specimens. For these
additional samples, we followed an extraction and amplification procedure
identical to that described above. Selection of a model of molecular substitu-
tion and Maximum Likelihood (ML) inference of a phylogenetic tree, based on
aligned data matrices of ITS, was inferred using IQTREE2 (Minh et al. 2020) and
bootstrap support for nodes was calculated, based on 1000 iterations using
fast-bootstrapping.

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624 145

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

Results
Phylogenetic relationships

Preliminary searches of the NCBI nucleotide BLAST database showed a sig-
nificant match between ITS sequences of the new species and core members
of subtribe Tetraneurinae, including Psilostrophe cooperi (A. Gray) Greene
(88.69%), Baileya multiradiata Harv. & A. Gray (88.89%), Tetraneuris acaulis
Greene (88.48%) and Hymenoxys lemmonii Cockerell (88.68%). The ML phylo-
genetic tree, based on the ITS alignment from Baldwin et al. (2002), resolved the
new species with very high (98 bs) support as nested in tribe Helenieae, where
it was more closely related to Psilostrophe than other members of subtribe
Tetraneurinae (Fig. 10). The new species + Psilostrophe, in turn, form the sister
lineage to the clade containing Amblyolepis setigera DC., Tetraneuris acaulis,
Tetraneuris scaposa (DC.) Greene, Hymenoxys ambigens var. floribunda (A.Gray)
W.L. Wagner, Hymenoxys hoopesii (A. Gray) Bierne, and Hymenoxys lemmonii
Cockerell. Addition of DNA sequence data (ITS) for five previously unsampled
taxa of Psilostrophe resolves all currently recognised minimum-rank taxa in this
genus as a monophyletic group separate from and sister to the new species.
Amongst taxa of Psilostrophe, the narrowly endemic P. bakeri is resolved as
sister to the rest of the genus, with P. sparsiflora next to diverge, followed by P
cooperi. Relationships amongst the highly-nested taxa P mexicana, P. gnaph-
alodes, P. tagetina and P villosa were not well supported with ITS data alone.

Micro-anatomy

Micro-morphological features targeted using SEM for their value in evaluating phy-
logenetic relationships in the Heliantheae alliance included the surface texture of
cypselae, pappus elements, trichomes, style trichomes, stigmatic surface, pollen
shape and glands of vegetative and reproductive structures. A comparative table
(Table 2) of these characteristics for genera of Tetraneurinae is given along with
plates of SEM images (Figs 11, 12). Micro-anatomical features of the new species
revealed by SEM include the dentate margins and pleated structure of hyaline pap-
pus scales, style branch apices with terminal papillae and short stipitate glands
that are present on the abaxial surface of ray and disc corolla lobes. Two types
of trichomes were observed. Cypselae trichomes appear stiff, linear and end in a
bifurcate tip. These conform with the cypselar trichomes observed in many other
Compositae, also called twin hairs (“Zwillingshaare”) by Hess (1938). Trichomes
on leaf tissues have a dilatated base (foot) that is notably wider than the rest of the
structure, which has an elongated, flagellate body, an apex that ends in a simple,
unbranched tip and a flexible, convoluted, helical structure, presumably giving the
plant its characteristic woolly appearance. These trichomes conform to the oblique
septate flagellate trichome type identified by Ramayya (1962), which occur in many
groups of Compositae and often render the plant surface tomentose. Pollen grains
of the new species measure approximately 20 micrometres in diameter and are
oblate spheroidal in shape, with evenly spaced, symmetrical echinate projections.
SEM images of representatives of related genera revealed similarities in the
paleaceous and finely pleated structure of the pappus (Figs 11H, 12A, E, I), pol-
len (Figs 11D, 12D), short-stalked stipitate glands (Figs 11C, 12C), stiff cypse-
lae trichomes with forked tips (Figs 11A, 12D), presence of the flexible helical

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624 146

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

trichomes that give the new species its woolly appearance (Fig. 11B) and style
branch apices with sweeping papillae (Figs 111, 12H). Some consistent differ-
ences that were noted between the new species and its sister genus Psilostro-
phe included the vestiture of disc and ray floret corolla lobes, which consist of
papillae in Psilostrophe, whereas the new species possesses helical trichomes
along ray throats and on abaxial surfaces of disc lobes (Figs 11F, 12F). Finer
variability was evident in the size and shape of the apex in paleaceous pappus
elements at shallower taxonomic scales (Figs 11H, 12A, E, |).

Taxonomic treatment

Ovicula biradiata Manley, gen. et. sp. nov.
urn:lsid:ipni.org:names:77356807-1
Figs 1-8

Description. Annuals, small, flowering plants usually 1—2(—3) cm tall, from less
than 1 cm wide to 3-7 cm across, whole plants densely white-tomentose. Root
single, thread-like, 0.5-1 mm wide at the plant base. Stems unbranched, erect
or branches, if evident, lateral, prostrate, spreading 1-4 cm in one or more di-
rections, internodes ca. 1 cm long. Leaves basal, mostly in tight clusters or at
nodes on short stems, proximal leaves spreading, distal ascending, petioles
1-4 mm long, blades ovate, 4-7 x 2.5-5 mm, entire, planar, gently involute
or nearly conduplicate. Heads heterogamous, borne singly, essentially sessile
(peduncles to ca. 1 mm long), obscured by woolly leaves. Involucres 5-7 x
4-6 mm, broadly funnelform to campanulate or subglobose. Phyllaries in 3
series, ca. 1-2 in outer series, ca. 1-2 in second series, outer slightly spread-
ing, those in outer 2 series 3-4 x 2-3 mm, ovate, inner series ca. 7, linear, ca.
2 mm wide, with scarious margins ca. 0.5 mm wide, densely white-tomentose.
Receptacles ca. 1 mm across, slightly saucer-shaped to flat, sometimes with
a very small conic enation from near centre, otherwise basically smooth or
with faint floret scars, epaleate. Ray florets 2(—3) per head, 3-6 x 0.6-1 mm
long, positioned on opposing sides, pistillate and fertile, strap-like; corolla tube
2-3 mm long, densely pilose distally, with wavy trichomes 0.3-1 mm long, lam-
inae 3-6 x 0.6-1 mm, 3-lobed, whitish, markedly 4-nerved proximally, 6-nerved
distally, nerves maroon, proximal portion of the abaxial ray laminae densely
covered with sessile or short stipitate glandular trichomes. Disc florets 10-12
per head, perfect and fertile; corolla pale yellow, ca. 2-3 mm long, tube 0.6-
0.9 mm long, throat 1.6-1.8 mm long, lobes 5, 0.1-0.3 mm long, distalmost
throat and lobes densely pilose with wavy trichomes 0.3-0.5 mm long; anthers
yellow, distal anther appendage narrowly obovate to subsagittate; style tip ap-
pendage truncate, apex papillate. Cypselae of ray and disc florets similar, 1.5-
2mm long, obconic-obpyramidal, slightly compressed or obscurely 4—5-angled
(prismatic), ribs 4-5, densely pubescent with straight, ascending-appressed,
silvery trichomes 0.5-0.9 mm long, minutely forked at tip, partially obscuring
the bases of pappus scales. Pappus of ray and disc florets similar, scales 5, ca.
1-3 x 0.8-1 mm, ovate, hyaline, with an apical arista ca. 1 mm long; the scales
spreading when dry (Figs 1-7). Chromosome number unknown.

Similar to members of tribe Helenieae (sensu Baldwin et al. (2002)), espe-
cially Tetraneuris, with its annual habit, radiate heads, phyllaries in 3 series,

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624 147

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

Figure 1. First photograph of Ovicula biradiata taken by Deb Manley on 2 March 2024.

convex, epaleate receptacles, ray florets pistillate and fertile, strap-like 3-lobed
ray floret laminae with prominent, coloured veins, cypselae obconical, faintly
ribbed and pappus of hyaline aristate scales, disc florets perfect and fertile,
corollas yellow, 5-lobed; differs from other Helenieae genera by its smaller size,
shorter stems, tightly clustered small leaves, greater tomentum density and
smaller, sessile heads with only 2(-3) ray florets.

Type. USA * Texas: Brewster Co.; Big Bend National Park, low gravelly lime-
stone exposure, eroded alluvial flats, NE of Dagger Mt.; elev. 800 m, 20 Apr
2024, Debra Manley 2, with C. Whiting, C. Hoyt, R Manning, and S. Menzies; holo-
type: SRSC 00058752 (BIBE 61799); isotype: CAS 1352777 (BIBE 61820).

Paratypes. USA + Texas; Brewster Co.: Big Bend National Park, low gravelly
limestone exposure, eroded alluvial flats, NE of Dagger Mt.; elev. 792.5 m, 20
Apr 2024, Debra Manley 3, with C. Whiting, C. Hoyt, P Manning, and S. Menzies;
BIBE 61800 (SRSC 00058751).

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624 148

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

Figure 2. Researchers examining individuals in habitat. A Patty Manning scanning the ground in appropriate habitat for
individuals of Ovicula biradiata B NPS botanist Carolyn Whiting photographing O. biradiata (circled in red). Photos by
Cathy Hoyt on 20 April 2024.

Figure 3. Known habitat of Ovicula biradiata. A, B Habitat with evident pediment slopes C slight habitat variation with
iron-bearing rocks present in calcareous cobbles D overview of population locality with individual plants circled in red
E close-up of individual plants in habitat illustrating cryptic appearance amongst calcareous surficial deposits. Photos
by James Bailey (A) in April 2024 and Deb Manley on 20 April 2024 (B-E).

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624 149

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

Etymology. The generic name from Latin Ovis “sheep” and -cula (diminu-
tive ending) references the dense woolly indumentum of this new plant. The
name honours the desert bighorn sheep (Ovis canadensis nelsonii), an iconic,
but threatened desert animal that is currently rebounding in this part of the
Chihuahuan Desert, providing hope for other rare species like O. biradiata. The
specific epithet biradiata references the typically two conspicuous ray florets,
occasionally three per head, positioned on opposing margins of the capitulum
(Figs 1, 4). A recommended common name for O. biradiata is “woolly devil”, in
reference to the woolly indumentum, the proximity of populations to the locality
known as Devil's Den and the tendency for the ray florets to resemble horns.

Distribution and phenology. Ovicula biradiata is known from limestone ped-
iments of eastern Big Bend National Park where only three small populations
have been found. Within these subpopulations, individual plants were abun-
dant, but short-lived, indicating an ephemeral life history. The species was
discovered on 2 March 2024 when plants were in full flower (Fig. 1). It is not
presently known how early the plants may produce flowers, but, in the same
general area, there are other species in several families that may bloom in early
February or even earlier. By late May, after a period of warm and dry weather,
the delicate annual plants had ceased vegetative growth and only desiccated
inflorescences could be found (Fig. 4).

Habitat and associated taxa. The general area of the three known locations
for the new taxon, as so far observed, consists of a broad floodplain composed

Figure 4. Images of Ovicula biradiata individuals representing the “small” growth habit that occurs most frequently in all
three known locations. Photographs by James Bailey in April 2024 (A), Kelsey Wogan on 27 April 2024 (B, E), Cathy Hoyt
on 2 March 2024 (C), Dana Sloan on 27 April 2024 (D).

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624 150

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

Figure 5. Examples of moderately sized individuals found occasionally throughout the known locations. Photographs by
Cathy Hoyt (A) & Deb Manley (B) on 2 March 2024 and James Bailey in April 2024 (C).

Figure 6. Largest individuals of Ovicula biradiata encountered by researchers in known localities thus far. Photographs by
Deb Manley (A, B) on 20 April 2024 & A. Michael Powell (C) on 27 April 2024.

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624 15]

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

SRSC
INU
00058752

Recession
_ BIBE-O1 702

Figure 7. Scan of the Holotype of Ovicula biradiata.

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624

N

ase
E 61799

Sul Ross State Univ. Herbarium (SRSC)

Ovicula biradiata D. L. Manley
Holotype
A.M. Powell Nov 2024

PLANTS OF TRANS-PECOS TEXAS
Brewster County

Gen. et sp. nov. Asteraceae

Big Bend Natl. Park, low gravelly to rocky limestone
exposure, eroded alluvial flats, Chihuahuan Desert scrub,
NE of Dagger ML.; 2610 ft. (795.53 m); associated plants,
Agave lechuguilla, Larrea, Krameria, Plantago,
Oenothera, Nerisyrenia camporum, Bouteloua, Grusonia
aggeria, Aristida, Dasyochloa pulchella, Ariocarpus
fissuratus.

Plants annual, locally abundant on the limestone
exposure; woolly, tiny, mostly inconspicuous, larger plants
to ca. 5 em across, with 1-few short, prostrate stems,
spreading; disc corollas pale yellow, ray floret ligules
whitish with maroon nerves.

Deb Manley 2 20 Apr 2024
with C. Whiting, C. Hoyt, P. Manning, and S. Menzies

152

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

ee

Beg
ea i
Nee
“ha
|
|
|
|

Figure 8. Line drawing of Ovicula biradiata gen. et. sp. nov. A Ray floret without cypsela B disc
floret without cypsela C cypsela D habit with close up of leaf surface illustrating nature of
indumentum. Illustration by Ellen Ruggia, based on material from the paratype (Manley 3).

of fine sand and clay sediments and braided with drainage. This alluvial ba-
sin terrain is fringed with low, gravel-capped pediments which then extend into
foothills and steeper slopes of a flanking limestone mountain range. The lo-
cations are within 625 m of each other and occur where a shallow layer of
mixed alluvial gravel and stones overlie bedrock of the Boquillas Formation.
This composite substrate occurs on both the Ernst and San Vicente members
of the formation and the observed habitat exposures consist of thinly-bedded
limestone, carbonate shale and siltstone overlain by Quaternary gravel, which
is a heterogeneous mix of surrounding geologic substrates. One site includes a
significant presence of iron-bearing rocks. The known locations receive full sun
throughout the day with very little shade provided by the sparse vegetation or
the flat topography (Figs 3, 4).

Widely-distributed species noted in the habitat include Vachellia vernicosa
(Britton & Rose) Seigler & Ebinger, Larrea tridentata (DC.) Coville, Tiquilia greggii
(Torr. & A. Gray) A.T. Richardson, T. hispidissima (Torr. & A. Gray) A.T. Richard-
son, Agave lechuguilla Torr., Thymophylla acerosa (DC.) Strother, Plantago sp.
L., Oenothera sp. L., Physaria sp. (Nutt.) A. Gray, Nerisyrenia camporum Greene,
Krameria sp. Loefl., Bouteloua sp. Lag., Aristida sp. L., Dasyochloa pulchella
(Kunth) Willd. ex Rydb., Ariocarpus fissuratus K. Schum., Echinocactus horizon-
thalonius Lem., Opuntia sp. (L.) Mill. and Grusonia aggeria (Ralston & Hilsenb.)
E.F. Anderson. Cryptobiotic soil is present in the habitat as well. See Figs 2, 3
for habitat photos and Fig. 9 for a distribution map.

Conservation. Ovicula biradiata is, so far, Known only from within a small area
ina seldom accessed part of Big Bend National Park. Nevertheless, the extreme-
ly narrow range and ephemerality of the species suggests that it is highly sensi-
tive to variable weather patterns. Recently, this part of the Chihuahuan Desert has

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624 153

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

Ovicula biradiata

Mexico

72,
S
)
aa
EA
qo

Ranch State
Park

{

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Area Proteg|

Big Bend
§ National
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Maderas
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Elena Area

Heat toko Ocampo Area

Protegida

Figure 9. Approximate range map of Ovicula biradiata. Geographical location of the known range of O. biradiata in Big
Bend National Park in Brewster County, Texas. The boundaries of the park are illustrated in dark green. The purple dot
marks the approximate area where three sub populations, each with abundant individuals of O. biradiata, were located.
An inset illustrates the location of the study site within the Chihuahuan Desert.

been under severe drought conditions and aridity is predicted to increase in this
region due to climate change (Climate Change Response Program 2024). Under
current IUCN guidelines for assessment of conservation status (IUCN Standards
and Petition Committee 2022), O. biradiata would, therefore, preliminarily quali-
fy as being vulnerable (VU) and under a high threat of extinction. More study is
needed on the reproductive biology and population structure of O. biradiata, as
well as potential threats to its habitat, to determine if the species should be listed
by the U.S. Fish and Wildlife Service under the Federal Endangered Species Act.
Due to the extreme sensitivity of the known collection sites the geocoordinates
of the locality have been withheld and the locality is obscured on the map (Fig. 9).

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624 154

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

6 6r Psilostrophe mexicana Villasefor 159
66 Psilostrophe gnaphalodes Sunderberg 12
Psilostrophe tagetina
Psilostrophe villosa raven 19297
Psilostrophe cooperi
Psilostrophe sparsiflora Butterwick 7526
Psilostrophe bakeri Cronquist 11645
Tetraneurinae
Ovicula biradiata Manley 2

Tetraneuris scaposa Turner 15128
Tetraneuris acaulis
Amblyolepis setigera
Hymenoxys ambigens
Hymenoxys hoopesii
Hymenoxys lemmonii
Baileya multiradiata
Baileya pleniradiata
Baileya pauciflora
Balduina uniflora . .
Gaillardia pul. Gaillardinae
Helenium bigelovii : :
Plateilemapalmeri | Plateileminae
Marshallia obo.
Marshallia caes.

oD)
©
we
c
xv
)
-

Pelucha trifida

Psathyrodes annua Marshallinae

Psathyrodes ramosissima
Trichoptilium incisum

0.07 subst.

Figure 10. Phylogenetic relationships of Ovicula biradiata and representative photographs of genera of Helenieae. A Max-
imum Likelihood (ML) phylogenetic tree of Helenieae, based on an aligned matrix of nrDNA sequence data from the
Internal Transcribed Spacer region. ITS sequences generated as part of this study have collector numbers indicated
to the right. Subtribes are indicated with text. Ovicula biradiata is in bold B Tetraneuris scaposa C Hymenoxys cooperi
D Ovicula biradiata E Psilostrophe tagetina F Amblyolepis setigera G Baileya pleniradiata H Gaillardia pulchella | Helenium
amphibolum. Photographs by Peri Lee Pipkin (C) and James Bailey (B, D-I).

Discussion

The discovery of Ovicula biradiata underscores that the task of documenting
and describing plant diversity is far from finished in the Chihuahuan Desert.
Furthermore, that discoveries are not limited to unexplored or unpopulated re-
gions and that interest and purposeful attention may still reveal novelties in
places such as National Parks that might be considered “well-trodden” or fully
understood. Encounters with novel plant species sufficiently different from their
relatives to warrant description at generic rank are very uncommon in North
America, but when they do occur, these often tend to be rare species associated
with arid or edaphic micro-habitats where selection for unique growth forms
is most pronounced (Stebbins 1952). Past examples of unique monospecific
genera discovered in deserts or unique soils include Apacheria chiricahuensis
C.T. Mason, Dedeckera eurekensis Reveal & J.T. Howell, Megacorax gracielanus
S. Gonzalez & W. Wagner and Yermo xanthocephalus Dorn. Conservation man-
agement of O. biradiata will depend on gathering more detailed observations
of its habitat specialisation, population size, reproductive biology, geographic
range and life cycle and these are data that should be gathered with urgency.

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624 155

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

As drought conditions continue to increase in frequency and severity, opportu-
nities to observe annual plants, including O. biradiata, may occur less frequently.

Evolutionary implications

With the addition of Ovicula biradiata, subtribe Tetraneurinae contains six gen-
era and 46 minimum rank taxa, making it the most diverse subtribe of Hele-
nieae (Baldwin 2009). Extant diversity in this group is concentrated in west-
ern North America where they are distributed across a broad range of habitats
from high mountains to low deserts (Baldwin and Wessa 2000). An ephemeral,
annual life history has evidently evolved multiple times in this group apart from
O. biradiata, as in Baileya pauciradiata Harvey & A. Gray, Tetraneuris linearifolia
Greene and Amblyolepis setigera DC., O. biradiata stands out amongst other
members of Tetraneurinae, however, for its minute stature, sessile heads and
densely woolly foliage that effectively camouflages the plant into a background
of coarse calcareous gravel. A salient, visually conspicuous characteristic of O.
biradiata is its ephemeral ray florets, which usually appear in pairs (Figs 1-6).

i aN

r ae rd
500m _Manleytypert Le 20k 06/13/2024

Figure 11. Scanning electron micrographs (SEM) of Ovicula biradiata. A Cypsela trichomes appear stiff, linear and end
in a bifurcate (forked) tip B trichomes on leaf surface with a flexible, helical structure C short-stalked capitate glands on
abaxial surface of ray corolla D pollen E ray floret without cypsela F disc corolla apex G anther column and exserted stig-
ma H pappus palea tip with fine pleated serrations I style branch apex, with papillate trichomes sweeping pollen grains.

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624 156

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

Phylogenetic relationships

Morphological features of Ovicula biradiata initially appeared to suggest a
close link between the new genus and Tetraneuris, including maroon linear
markings on the ray floret corollas (typically only visible on the abaxial face
of the ray lamina in Tetraneuris), cypselae with a dense indument of fork-
tipped trichomes and pappus of 4-6 hyaline, aristate scales. Some combi-
nation of these traits is present in other genera of subtribe Tetraneurinae,
however, suggesting they may be shared ancestral characteristics. Molecular
phylogenetic (ITS) data support a more distant relationship between O. bira-
diata and Tetraneuris than was expected from morphology and resolves the
new genus as the sister lineage to the paper flowers (Psilostrophe). Ovicula
biradiata bears resemblance to Psilostrophe in terms of its dense tomentose

Figure 12. Scanning electron micrographs (SEM) of various genera of Tetraneurinae. A Pappus of Amblyolepis setigera
B pollen of A. setigera C short-stalked capitate glands on disc corolla of Baileya pauciradiata D stiff, twin hairs on cypsela
of Hymenoxys cooperi E hyaline, aristate palea-like pappus of Hymenoxys cooperi F vesicular trichomes on abaxial surface
of disc corolla lobes in Psilostrophe bakeri G ridges on the surface of a cypsela in P bakeri H sweeping papillate trichomes
on style branch apices in Tetraneuris scaposa | paleaceous pappus of T: scaposa with terminal, antrorsely setose bristle.

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624 157

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

trichomes, leaves that are both basal and cauline and typically non-scapiform
heads. ITS is a relatively easy-to-sequence DNA region that has been used for
decades to resolve relationships at a variety of scales in Compositae, yet it
represents only one line of genetic evidence. The possibility that conflicting
relationships amongst genera of Tetraneurinae may be supported by alter-
native DNA regions or potentially reveal a role for other processes such as
hybridisation in producing enigmatic evolutionary lineages like O. biradiata,
are hypotheses that are worth exploring in future studies.

Micro-anatomy

Micro-anatomical observations enabled by SEM revealed several characteris-
tic features noted as diagnostic for the tribe (e.g. as Gaillardiinae in Robinson
(1981)). These include a style apex with sweeping papillae, stigma with two
receptive lines and oblate spheroidal pollen with regular echinate spines. Some
characters revealed by SEM images for O. biradiata, include the pleated, serrate
structural anatomy of the aristate pappus scales and foliar trichomes with a
flagellate, helical body, which make up the plants woolly-tomentose indumen-
tum. Short-stipitate glands present on the ray and disc corollas of O. biradi-
ata resemble those found in many Compositae, which are often associated
with sesquiterpene lactone synthesis (Robinson 2009). Phytochemical stud-
ies of Compositae, including members of tribe Helenieae, have yielded unique
chemical compounds (e.g. Helenolins) with potential for anti-inflammatory and
anti-cancer activity. The presence of short-stipitate glands in O. biradiata sug-
gests this new species might contain secondary metabolites worthy of study
for their potential medicinal value.

Finally, to encourage further study of this fascinating group, we present an
updated key to the genera of Tetraneurinae, including Ovicula, based on in-
formation compiled from floras and observations of herbarium specimens in
SRSC and CAS:

Key to the genera of Tetraneurinae

1 Phyllaries in 2 series, outer herbaceous, inner very short, hyaline, scale-
like; cypselae 10-ribbed, the ribs densely tan-pubescent; herbage notably
pleasant-scented; annuals; proximal leaves usually oblanceolate to broad-
ly spatulate, semi-clasping, blades with long brownish trichomes, mostly
OMACMESIALOIAS LR. # Beceem, 8S AO enh ers eae Amblyolepis

—- Phyllaries in 1-3 series, all herbaceous, inner not short, sometimes with
scarious margins; cypselae 2—5-ribbed or angled, often weakly so, faintly
striate in some taxa, the ribs or angles gland-dotted, naked or pubescent
with long or short trichomes, these whitish or silvery; herbage lacking no-
table scent; annuals, biennials or perennials; proximal leaves of various
shapes, not clasping, trichomes if present not long and brownish, instead
white or colourless, often densely toMeNtOSE ..............cccccccscccesseeeeessseeeees 2

2 Foliage glabrous or tomentellous (sparsely hairy), at the base often wool-
ly, densely silky in H. subintegra; outer phyllaries usually partially connate;
ray corollas ultimately withering and falling...................ccceee Hymenoxys

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624 158

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

- Foliage densely woolly to tomentellous, sometimes glabrous; outer phyl-
laries distinct; ray corollas usually persistent in fruit, except readily dis-
[GCS CITT VIC Ciao ets 8 ORS ren eee aA aa nlts aa cainachan anit abana tecatees tins cadec 3

3. Ray florets 2(-3), corollas white with maroon nerves, readily dislodged
from developing cypselae, laminae 0.6-1 mm wide; plants minute an-
nuals, usually 1-2(-3) cm tall, 1-7 cm wide, branches if present lateral,
prostrate, whole plants densely woolly; leaves crowded basally, entire, 4-7
pF: LONG 25S WAG e ec teeta. dos cect eee es eteree sae come dee | Ovicula

- Ray florets 1-55, rarely 0, corollas yellow or orange, with yellow or ma-
roon nerves, usually persistent in fruit, laminae 0.7-20 mm wide; plants
annuals, biennials or perennials, 5-100 cm tall (except 2-40 cm in sev-
eral species of Tetraneuris), stems ascending to erect, scapiform in most
Tetraneuris, glabrous or tomentellous to densely wololy; leaves basal or
cauline, densely woolly or not, entire to pinnately lobed, 20-120 mm long,

BBO MMM WIGS. sh teed tels cil hs wos dears tonne tubadernctsne ode cz tiohe watts nehton aaentalivnes ccnates eae 4
4 Pappus absent; leaf blades woolly, mostly 3-lobed or pinnate ........ Baileya
- Pappus of 4-8 hyaline scales; leaf blades tomentellous to woolly, margins
mostly entire, sometimes toothed or lobed............c cc ccecccceeeesceeeceseseeees 5

5 Ray florets 7-27, except none in T. verdiensis; disc florets 20-—200+; plants
tomentellous to somewhat woolly, scapiform, except stems erect in the
annual T. linearifolia; heads mostly Single ..............:ccceceeseeeees Tetraneuris

- Ray florets usually 1-6; disc florets usually 5-17; plants woolly, not scapi-
form; heads single (in P. cooperi) or in clusters with peduncles 0.5-2.5 cm
OMIMIOIE, LONG sazcch wscves & Actes ck et vec. dopeesccel beetes eats trast or ReE a eneter ne Psilostrophe

Acknowledgements

The research in Big Bend National Park was carried out under Scientific Re-
search and Collecting Permit BIBE-2024-SCI-0015 (Study: BIBE-00694). This
study was carried out with the support of the Center for Comparative Genom-
ics and Scanning Electron Microscopy (SEM) Lab at the California Academy of
Sciences. Keily Peralta was supported by the Summer Systematics Institute,
a programme of NSF (DBI 2243994) and the Robert T. Wallace endowment
for undergraduate education. Isaac Lichter Marck was supported by NSF DBI
2209393. The botanical illustration was funded by the Babe Turner Herbarium
Endowment Fund at SRSC. For productive suggestions that improved the manu-
script, we thank David Keil, Mauricio Bonifacino de Leon, Oscar Vargas and one
anonymous reviewer. The authors would also like to thank Cathy Hoyt (co-dis-
coverer), Shirley Powell, Dana Sloan, Ellen Ruggia, Patty Manning, Jimmy Duke,
Stephen Menzies, Jim Henrickson, Jesse Kelsch, Shea Cadrin, James Bailey,
Joey Santore, Ricardo Kreibel, Emily Magnaghi, Sarah Jacobs, Gary Williams,
Athena Lam, Grace Kim, Tom Daniels, Bruce Baldwin and Sophia Winitsky. Key
technical assistance was provided by Wren and Alice Marck.

Additional information

Conflict of interest

The authors have declared that no competing interests exist.

PhytoKeys 252: 141-162 (2025), DOI: 10.3897/phytokeys.252.137624 159

Debra L. Manley et al.: Ovicula biradiata gen. et. sp. nov. (Compositae)

Ethical statement
No ethical statement was reported.

Funding

No funding was reported.

Author contributions

Conceptualization: AMP KAW, DLM, IHLM. Data curation: KAW, AMP, DLM, ACC, KP,
IHLM. Formal analysis: IHLM, KP. Funding acquisition: IHLM. Investigation: AMP, KAW,
DLM, CVW. Methodology: IHLM. Project administration: CVW, AMP, DLM, KAW. Supervi-
sion: AMP. Visualization: KAW, KP. Writing — original draft: IHLM, AMP. Writing — review
and editing: DLM, IHLM, AMP, ACC, KP KAW, CVW.

Author ORCIDs

Debra L. Manley © https://orcid.org/0009-0003-9345-41 66

Isaac H. Lichter Marck © https://orcid.org/0000-0003-3575-6003
Arturo Castro Castro © https://orcid.org/0000-0002-2864-5180
Carolyn V. Whiting © https://orcid.org/0000-0002-7665-1577

Data availability

All of the data that support the findings of this study are available in the main text.

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